Characteristics of Rotary Draw-Bent Tubes for the Hydroforming

2011 ◽  
Vol 213 ◽  
pp. 320-324
Author(s):  
Byeong Don Joo ◽  
Jeong Hwan Jang ◽  
Hyun Jong Lee ◽  
Young Hoon Moon
Keyword(s):  
Cross Section ◽  
Structural Strength ◽  
Dimensional Accuracy ◽  
Thickness Variation ◽  
Important Process ◽  
Rotary Draw Bending ◽  
Higher Dimensional ◽  
Bending Process ◽  
Geometric Size ◽  
Draw Bending

Hydroformed parts have higher dimensional accuracy, structural strength, and dimensional repeatability. The pre-bending process is an important process for the successful hydroforming in the case where the perimeter of the blank is nearly the same as that of final product. At initial pre-bending stage, the variations of wall thickness and cross-section have effects on the accuracy of final products and quality. Because of a relatively excellent productive velocity, geometric size precision and reliance of product qualities, rotary draw bending is widely used. This study shows the bendability such as cross-section ovality, springback ratio and thickness variation in the various conditions of materials.

Deformation Behaviors of Tube Rotary-Draw Bending Filled with Steel Balls

2011 ◽  
Vol 328-330 ◽  
pp. 1403-1407 ◽  
Author(s):  
Song Chao Shi ◽  
Lian Fa Yang ◽  
Chen Guo
Keyword(s):  
Cross Section ◽  
Wall Thickness ◽  
Rotary Draw Bending ◽  
Simulation Based ◽  
Bending Process ◽  
Deformation Behaviors ◽  
Draw Bending ◽  
Steel Balls ◽  
Internal Pressures

Wrinkling, wall thickness overthinning and cross-section distorting are main defects that seriously affect the forming quality of the tube in bending process. In this paper, numerical simulation based on PAM-STAMP 2G is conducted for the tube rotary-draw bending filled with steel balls as pressure transferring medium to analyze the deformation behaviors under various internal pressures. The results show that, tube bending filled with steel balls as pressure transferring medium can effectively restrain the defects of wrinkling and cross-section distorting. In addition, wrinkling and cross-section distorting of the bent tube decrease, the wall thickness thickening at the intrados of the bent tube decreases while the wall thickness thinning at the extrados increases with the internal pressure.

Numerical Research on High-Strength Rectangular Section Steel Tube in Rotary-Draw Bending

2014 ◽  
Vol 620 ◽  
pp. 417-423 ◽  
Author(s):  
Zhong Wen Xing ◽  
Zhi Wei Xu ◽  
Hong Liang Yang ◽  
Cheng Xi Lei
Keyword(s):  
High Strength ◽  
Element Model ◽  
Steel Tube ◽  
Rotary Draw Bending ◽  
Rectangular Section ◽  
Control Variate ◽  
Fillet Radius ◽  
Bending Process ◽  
Bending Radius ◽  
Draw Bending

A finite element model of high-strength rectangular section steel tube in rotary-draw bending is established to study the stress and strain in the bending process. Based on control variate method, this paper analyzes the influence laws of three geometric parameters on rotary-draw bending. The results show that bending radius is the most important factor, forming property increases significantly with the increase of bending radius, the trends of cracking and wrinkling are all decreased. The thickness of wall has influence on the strain of inwall, thinner tube may cause crack and wrinkle. Fillet radius has no effect on ektexine, the strain of inwall decreases slightly with the increase of fillet radius.

Numerical and Experimental Research on Warm Tension-Rotation Bending of Extruded AZ31 Profile

2011 ◽  
Author(s):  
Shi-hong Zhang ◽  
Han Xiao ◽  
Jin-song Liu ◽  
Ming Cheng
Keyword(s):  
Main Parameter ◽  
Geometric Dimension ◽  
Element Model ◽  
Bending Test ◽  
Test Machine ◽  
Rotary Draw Bending ◽  
Bending Process ◽  
Forming Temperature ◽  
Dimensional Variation ◽  
Draw Bending

Magnesium alloy profiles have attracted more and more attention in automobile and aerospace industries. The rotary draw bending process is suitable to form profiles. A bending test machine is developed to conduct AZ31 profile bending experiment. A 3D elastic-plastic thermo-mechanical coupled finite element model is established and validated by experiment. The effects of process parameters on the geometric dimension of the profile were analyzed by using experimental and numerical methods. The results indicate that the pretension amount is the main parameter which influences the geometric dimension of the bent profile, then the forming temperature, following the bending angle. The dimensional variation of the middle-rib is relatively little, and the dimensional variations of the inside and the outside of the bent profile are large.

Side Wrinkling Characteristics in Rotary-Draw Bending Process of Thin-Walled Rectangular 3A21 Tube

2011 ◽  
Vol 697-698 ◽  
pp. 356-360
Author(s):  
Gang Yao Zhao ◽  
Yu Li Liu ◽  
Shan Tian ◽  
He Yang
Keyword(s):  
Wave Height ◽  
Three Dimensional ◽  
Element Model ◽  
Rotary Draw Bending ◽  
Bending Process ◽  
Dimensional Finite Element ◽  
Thin Walled ◽  
Draw Bending ◽  
Three Dimensional Finite Element ◽  
Aluminum Alloy Tube

Side wrinkling may be produced during rotary-draw bending process of thin-walled rectangular 3A21 aluminum alloy tube if the process parameters are inappropriate. To study the side wrinkling behavior, a three-dimensional finite-element model of the process was developed based on ABAQUS/Explicit code and its reliability was validated by experiment. Then, the side wrinkling characteristics of the tube were investigated. The results show that the side wrinkling wave height in the inner edge of the tube is smaller than that in the out edge of the tube, and the side wrinkling wave height in the neutral layer of the tube is minimal. With the bending process, the side wrinkling wave goes through producing, developing and stabilizing three stages in turn. After bending angle reached 30°, the side wrinkling wave height keeps almost unchanged. Furthermore, the number of the half side wrinkling wave increases evenly.

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